Revenue - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Disaggregation of Revenue [Line Items]
Total	$ 421,720	$ 267,016	$ 166,028
MongoDB Atlas-related
Disaggregation of Revenue [Line Items]
Total	162,510	60,241	11,265
Other subscription
Disaggregation of Revenue [Line Items]
Total	237,316	188,150	140,588
Services
Disaggregation of Revenue [Line Items]
Total	21,894	18,625	14,175
Americas
Disaggregation of Revenue [Line Items]
Total	272,358	172,688	110,616
EMEA
Disaggregation of Revenue [Line Items]
Total	118,660	79,757	48,129
Asia Pacific
Disaggregation of Revenue [Line Items]
Total	$ 30,702	$ 14,571	$ 7,283